Improvement in sled-propellers



D. W. De FOREST.

SLED-PROPELLER. N 170 715 Patented Dec. 7,1875. o. Q

Q 'zzzdglfaag 560g! aig/iwwg NPETERS, PNOTO-UTHOGRAPHER, WASHINGTON. D.C.

UNITED STATES PATENT OFFICE.

DAVID W. DE FOREST, OF BROOKLYN, NEW YORK.

IMPROVEMENT IN SLED-PROPELLERS.

Specification forming part of Letters Patent No. 170,7 15, datedDecember 7, 1875; application filed November 24, 1875.

.To all whom it may concern:

Be it known that I, DAVID W. DE FOREST, of Brooklyn, in the county ofKings and State of New York, have invented an Improvement in SeliPropellin g Sleds, of which the following is a specification Thisinvention relates to that class of devices designed to enable a sled tobe propelled by the manual effort of the person riding thereon; and itsobject is to provide a means for such propulsion which shall operatewith positive movements, but at the same time be under the perfect andabsolute control of the person using the same, both in urging the sledalong and in returning the propellingstaff back to its original positionafter each propulsive stroke, preparatory to another. To this end theinvention comprisesa propelling-staff, pivoted to the upper extremity ofa swinging link, the lower end of which is pivoted to the side of thesled, the whole being so constructed and combined that the apparatus maybe operated by the grasp of the operator upon the staff itself, insteadof upon a lever actuating such staff, as has been proposed in otherplans for self-propelling sleds.

By this novel combination of parts, embracing a new modus operandi, thehereinbeforespecified object is effectually secured. It is to beunderstood that ordinarily, in practice, the propelling devices are tobe applied to the sled in duplicate-one set on one side of the sled, andone on the other.

Figure l is a side view of a sled made and fitted accordii'ig to myinvention. Fig. 2 is a plan view of the same. Fig. 3 is a side view ofthe same.

A is the sled, of any ordinary or suitable construction, and,ordinarily, of the size and shape of a hand-sled, so termed. As thedevices are represented in the drawings as applied in duplicate-one seton one side of the sled, and one set on the other side thereof-thedescription of one set, as follows, will suflice for both: E is a link,pivoted at its lower end to the side of the sled, as represented morefully at cin Figs. 1 and 2. O is a propelling-staff, which is pivoted ator near its top or upper end to the upper extremity of the link B, asshown at b, the lower extremity of the staff being made suflicientlysharp or acute to insure its holding or catching upon the ice, compactsnow, or other smooth surface, upon which the sled is intended to run.The upper end portion of the staff may be made to project above orbeyond the pivot b, by which it is connected to the link B, asrepresented in Fig. 1, in which case such upwardly-projecting portionconstitutes a handle, 0, on the staff. When preferred, however, thestaff is pivoted at its extreme end to the link, as shown in Fig. 3, inwhich latter case an inwardly-projecting handle, 0, is provided to thestaff at a suitable distance below its pivot b.

The sled being provided, as herein previously explained, With theaforesaid devices in duplicate, the operation of the mechanism in thepropulsion of the sled is as follows: The operator, seated upon the sledin the usual manner, grasps one of the staves O in each hand, either bythe handle 0, when the staves are made with such, or by the handles 0,when such are provided. The staves are then brought downward andbackward against the ice, snow-covered ground, or other surface uponwhich the sled is to run, and, coming in contact therewith, find pointsof resistance, which cause the force applied to the staves in a rearwarddirection to propel the sled in an opposite or forward direction. Whenthe limit of the rearward stroke of the staves is reached the staves arelifted clear of the ground, and moved forward for a repetition of thestroke. It will be seen that in this operation the force applied to thestaves G is caused to act directly in the propulsion of the sled; thatthe return movement of the staves,by bringing them clear of the ground,prevents all digging, loss of power, and retardatiouof the sled; andthat the staves, being pivoted to the swinging links B, have theirmovements regulated and controlled, so far as is necessary to secure theaccurate movement of the staves, and yet leave the latter free to bemoved to any extent of stroke desired, and to be brought clear of theground in their forward or return movement, as hereinbefore set forth.

I do not claim a propelling-staff operated by an actuating-lever, forthe reason that such device is essentially different from my the wholeconstructed'and combined for use herein-specified invention; but andoperation substantially as and for-- the What I do claim as my inventionis purpose described. The stafi' G, constructed to be grasped by DAVIDW. DE FOREST. the hand of the operator, and the link B, piv- Witnesses:oted at its upper extremity t0 the stafi G, and W. MAKEPEAOE EDWARDS, atits lower extremity to the side of the sled, I H. WELLS, Jr.

